Differences in the expression of five senescence markers in oral cancer, oral leukoplakia and control samples in humans

A Conversation with ChatGPT on Contentious Issues in Senescence and Cancer Research

Artificial intelligence (AI) platforms, such as Generative Pretrained Transformer (ChatGPT), have achieved a high degree of popularity within the scientific community due to their utility in providing evidence-based reviews of the literature. However, the accuracy and reliability of the information output and the ability to provide critical analysis of the literature, especially with respect to highly controversial issues, has generally not been evaluated. In this work, we arranged a question/answer session with ChatGPT regarding several unresolved questions in the field of cancer research relating to therapy-induced senescence (TIS), including the topics of senescence reversibility, its connection to tumor dormancy, and the pharmacology of the newly emerging drug class of senolytics. ChatGPT generally provided responses consistent with the available literature, although occasionally overlooking essential components of the current understanding of the role of TIS in cancer biology and treatment. Although ChatGPT, and similar AI platforms, have utility in providing an accurate evidence-based review of the literature, their outputs should still be considered carefully, especially with respect to unresolved issues in tumor biology. SIGNIFICANCE STATEMENT: Artificial Intelligence platforms have provided great utility for researchers to investigate biomedical literature in a prompt manner. However, several issues arise when it comes to certain unresolved biological questions, especially in the cancer field. This work provided a discussion with ChatGPT regarding some of the yet-to-be-fully-elucidated conundrums of the role of therapy-induced senescence in cancer treatment and highlights the strengths and weaknesses in utilizing such platforms for analyzing the scientific literature on this topic.

Computational identification of natural senotherapeutic compounds that mimic dasatinib based on gene expression data

The major risk factor for chronic disease is chronological age, and age-related chronic diseases account for the majority of deaths worldwide. Targeting senescent cells that accumulate in disease-related tissues presents a strategy to reduce disease burden and to increase healthspan. The senolytic combination of the tyrosine-kinase inhibitor dasatinib and the flavonol quercetin is frequently used in clinical trials aiming to eliminate senescent cells. Here, our goal was to computationally identify natural senotherapeutic repurposing candidates that may substitute dasatinib based on their similarity in gene expression effects. The natural senolytic piperlongumine (a compound found in long pepper), and the natural senomorphics parthenolide, phloretin and curcumin (found in various edible plants) were identified as potential substitutes of dasatinib. The gene expression changes underlying the repositioning highlight apoptosis-related genes and pathways. The four compounds, and in particular the top-runner piperlongumine, may be combined with quercetin to obtain natural formulas emulating the dasatinib + quercetin formula.

Establishment of skin cutaneous melanoma prognosis model based on vascular mimicry risk score

Studies have indicated that Vascular mimicry (VM) could contribute to the unfavorable prognosis of skin cutaneous melanoma (SKCM). Thus, the objective of this study was to identify therapeutic targets associated with VM in SKCM and develop a novel prognostic model. Gene expression data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) were utilized to identify differentially expressed genes (DEGs). By intersecting these DEGs with VM genes, we acquired VM-related DEGs specific to SKCM, and then identified prognostic-related VM genes. A VM risk score system was established based on these prognosis-associated VM genes, and patients were then categorized into high- and low-score groups using the median score. Subsequently, differences in clinical characteristics, gene set enrichment analysis (GSEA), and other analyses were further presented between the 2 groups of patients. Finally, a novel prognostic model for SKCM was established using the VM score and clinical characteristics. 26 VM-related DEGs were identified in SKCM, among the identified DEGs associated with VM in SKCM, 5 genes were found to be prognostic-related. The VM risk score system, comprised of these genes, is an independent prognostic risk factor. There were significant differences between the 2 patient groups in terms of age, pathological stage, and T stage. VM risk scores are associated with epithelial biological processes, angiogenesis, regulation of the SKCM immune microenvironment, and sensitivity to targeted drugs. The novel prognostic model demonstrates excellent predictive ability. Our study identified VM-related prognostic markers and therapeutic targets for SKCM, providing novel insights for clinical diagnosis and treatment.

Therapy-induced senescence as a component of tumor biology: Evidence from clinical cancer

Therapy-Induced Senescence (TIS) is an established response to anticancer therapy in a variety of cancer models. Ample evidence has characterized the triggers, hallmarks, and functional outcomes of TIS in preclinical studies; however, limited evidence delineates TIS in clinical cancer (human tumor samples). We examined the literature that investigated the induction of TIS in samples derived from human cancers and highlighted the major findings that suggested that TIS represents a main constituent of tumor biology. The most frequently utilized approach to identify TIS in human cancers was to investigate the protein expression of senescence-associated markers (such as cyclins, cyclin-dependent kinase inhibitors, Ki67, DNA damage repair response markers, DEC1, and DcR1) via immunohistochemical techniques using formalin-fixed paraffin-embedded (FFPE) tissue samples and/or testing the upregulation of Senescence-Associated β-galactosidase (SA-β-gal) in frozen sections of unfixed tumor samples. Collectively, and in studies where the extent of TIS was determined, TIS was detected in 31-66% of tumors exposed to various forms of chemotherapy. Moreover, TIS was not only limited to both malignant and non-malignant components of tumoral tissue but was also identified in samples of normal (non-transformed) tissue upon chemo- or radiotherapy exposure. Nevertheless, the available evidence continues to be limited and requires a more rigorous assessment of in vivo senescence based on novel approaches and more reliable molecular signatures. The accurate assessment of TIS will be beneficial for determining its relevant contribution to the overall outcome of cancer therapy and the potential translatability of senotherapeutics.

Aging and oral squamous cell carcinoma development: the role of cellular senescence

The gradual accumulation and inadequate renewal of senescent cells over time drive organismal aging. Senescent cells undergo altered gene expression and release inflammatory mediators collectively termed the senescence-associated secretory phenotype (SASP), which significantly contributes to a spectrum of age-related disorders, including cancer. In the context of carcinogenesis, the SASP produced by senescent cells has been implicated in the promotion of epithelial cancers, including oral squamous cell carcinoma (OSCC), the most common form of oral cancer. Senescent cells within the tumor microenvironment release factors that amplify the growth and invasiveness of neighboring cancer cells. Senotherapeutics, including senolytics and senomorphics, emerge as promising modalities to target senescent cells and their associated inflammatory factors, thereby opening novel avenues for augmenting the efficacy of cancer treatments. Here, we review the general aspects of cellular senescence, focusing on the relation between senescence-related inflammation with cancer development. We also analyze the available evidence linking cellular senescence with OSCC, highlighting possible clinical applications.

Emerging Role of Decoy Receptor-2 as a Cancer Risk Predictor in Oral Potentially Malignant Disorders

The aim of this study was to evaluate the expression of the senescence markers, Decoy Receptor 2 (DcR2) and Differentiated Embryo-Chondrocyte expressed gen 1 (DEC1), in oral potentially malignant disorders (OPMDs) to ascertain their possible association with oral cancer risk. The immunohistochemical analysis of DcR2 and DEC1 expression (along with p16 and Ki67 expression) was carried out in 60 patients with clinically diagnosed oral leukoplakia. Fifteen cases (25%) subsequently developed an invasive carcinoma. Correlations between protein marker expression, histological grade and oral cancer risk were assessed. DcR2, DEC1 and Ki67 protein expressions were found to correlate significantly with increased oral cancer risk, and also with an increased grade of dysplasia. Multivariate analysis demonstrated that DcR2 and Ki67 expression are independent predictors of oral cancer development. Our results evidence for the first time the potential of DcR2 as an early biomarker to assess oral cancer risk in patients with oral leukoplakia (HR = 59.7, p = 0.015), showing a superior predictive value to histology (HR = 4.225, p = 0.08). These findings reveal that the increased expression of DcR2 and DEC1 occurred frequently in OPMDs. In addition, DcR2 expression emerges as a powerful biomarker for oral cancer risk assessment in patients with oral leukoplakia.

Senolytic Therapy: A Potential Approach for the Elimination of Oncogene-Induced Senescent HPV-Positive Cells

Senescence represents a unique cellular stress response characterized by a stable growth arrest, macromolecular alterations, and wide spectrum changes in gene expression. Classically, senescence is the end-product of progressive telomeric attrition resulting from the repetitive division of somatic cells. In addition, senescent cells accumulate in premalignant lesions, in part, as a product of oncogene hyperactivation, reflecting one element of the tumor suppressive function of senescence. Oncogenic processes that induce senescence include overexpression/hyperactivation of H-Ras, B-Raf, and cyclin E as well as inactivation of PTEN. Oncogenic viruses, such as Human Papilloma Virus (HPV), have also been shown to induce senescence. High-risk strains of HPV drive the immortalization, and hence transformation, of cervical epithelial cells via several mechanisms, but primarily via deregulation of the cell cycle, and possibly, by facilitating escape from senescence. Despite the wide and successful utilization of HPV vaccines in reducing the incidence of cervical cancer, this measure is not effective in preventing cancer development in individuals already positive for HPV. Accordingly, in this commentary, we focus on the potential contribution of oncogene and HPV-induced senescence (OIS) in cervical cancer. We further consider the potential utility of senolytic agents for the elimination of HPV-harboring senescent cells as a strategy for reducing HPV-driven transformation and the risk of cervical cancer development.

Molecular Biomarkers of Malignant Transformation in Head and Neck Dysplasia

Head and neck squamous cell carcinoma (HNSCC) and its treatments are associated with substantial morbidity, often resulting in cosmetic deformity and loss of physiologic functions including speech and swallowing. Despite advancements in treatment, 5-year survival rates for mucosal malignancies remain below 70%. Effective prevention of HNSCC demands an understanding of the molecular pathways of carcinogenesis. Specifically, defining features of pre-cancerous dysplastic lesions that indicate a better or worse prognosis is necessary to help identify patients who are likely to develop a carcinoma and allow a more aggressive approach to management. There remains a need for identification of biomarkers that can provide both early prognostic and predictive value in clinical decision-making by serving as both therapeutic targets as well as predictors of therapy response. Here, we comprehensively review the most frequently altered molecular biomarkers of malignant transformation in head and neck dysplasia. These markers are involved in a wide range of cellular processes in head and neck carcinogenesis, including extracellular matrix degradation, cell motility and invasion, cell-cell adhesion, solute transport, immortalization, metabolism, the cell cycle and apoptosis, transcription, and cell signaling.

Senescence-associated secretory phenotype and its impact on oral immune homeostasis

The senescence-associated secretory phenotype (SASP), which accumulates over the course of normal aging and in age-related diseases, is a crucial driver of chronic inflammation and aging phenotypes. It is also responsible for the pathogenesis of multiple oral diseases. However, the pathogenic mechanism underlying SASP has not yet been fully elucidated. Here, relevant articles on SASP published over the last five years (2017-2022) were retrieved and used for bibliometric analysis, for the first time, to examine SASP composition. More than half of the relevant articles focus on various cytokines (27.5%), growth factors (20.9%), and proteases (20.9%). In addition, lipid metabolites (13.1%) and extracellular vesicles (6.5%) have received increasing attention over the past five years, and have been recognized as novel SASP categories. Based on this, we summarize the evidences demonstrating that SASP plays a pleiotropic role in oral immunity and propose a four-step hypothetical framework for the progression of SASP-related oral pathology-1) oral SASP development, 2) SASP-related oral pathological alterations, 3) pathological changes leading to oral immune homeostasis disruption, and 4) SASP-mediated immune dysregulation escalating oral disease. By targeting specific SASP factors, potential therapies can be developed to treat oral and age-related diseases.

Cellular senescence: the good, the bad and the unknown

Cellular senescence is a ubiquitous process with roles in tissue remodelling, including wound repair and embryogenesis. However, prolonged senescence can be maladaptive, leading to cancer development and age-related diseases. Cellular senescence involves cell-cycle arrest and the release of inflammatory cytokines with autocrine, paracrine and endocrine activities. Senescent cells also exhibit morphological alterations, including flattened cell bodies, vacuolization and granularity in the cytoplasm and abnormal organelles. Several biomarkers of cellular senescence have been identified, including SA-βgal, p16 and p21; however, few markers have high sensitivity and specificity. In addition to driving ageing, senescence of immune and parenchymal cells contributes to the development of a variety of diseases and metabolic disorders. In the kidney, senescence might have beneficial roles during development and recovery from injury, but can also contribute to the progression of acute kidney injury and chronic kidney disease. Therapies that target senescence, including senolytic and senomorphic drugs, stem cell therapies and other interventions, have been shown to extend lifespan and reduce tissue injury in various animal models. Early clinical trials confirm that senotherapeutic approaches could be beneficial in human disease. However, larger clinical trials are needed to translate these approaches to patient care.

Podoplanin Expression Independently and Jointly with Oral Epithelial Dysplasia Grade Acts as a Potential Biomarker of Malignant Transformation in Oral Leukoplakia

Our aim was to evaluate the expression of biomarkers, CD44v6, CD147, EGFR, p53, p63, p73, p16, and podoplanin in oral leukoplakias (OL) and to assess their potential for prediction of malignant transformation (MT). We analyzed the expression of CD44v6, CD147, EGFR, p53, p63, p73, p16, and podoplanin by immunohistochemistry in 52 OL, comprised of 41 low-grade (LG) dysplasia and 11 high-grade (HG) cases. Twelve healthy normal tissues (NT) were also included. Univariate and multivariate analysis were performed to evaluate any association with MT. Variable expression among the studied markers was observed, with a significant increase of high expression from NT to LG and HG cases in CD44v6 (p = 0.002), P53 (p = 0.002), P73 (p = 0.043), and podoplanin (p < 0.001). In multivariate analysis, cases with high podoplanin score showed a significant increased risk of MT (HR of 10.148 (95% CI of 1.503−68.532; p = 0.017). Furthermore, podoplanin combined with binary dysplasia grade obtained a HR of 10.238 (95% CI of 2.06−50.889; p = 0.004). To conclude, CD44v6, p53, p73, and podoplanin showed an increasing expression along the natural history of oral carcinogenesis. Podoplanin expression independently or combined with dysplasia grade could be useful predictive markers of MT in OL.

The vulnerable primed cancer stem cells in disguise: demystifying the role of Maspin

Epithelial-specific Maspin is widely known as a tumor suppressor. However, while the level of maspin expression is inversely correlated with tumor grade and stage, emerging clinical evidence shows a correlation between seemingly better differentiated tumor cells that express Maspin in both the nucleus and the cytoplasm, (n + c)Maspin, with a poor prognosis of many types of cancer. Biological studies demonstrate that Maspin plays an essential role in stem cell differentiation. In light of the recently established characterization of primed stem cells (P-SCs) in development, we propose, for the first time, that cancer stem cells (CSCs) also need to undergo priming (P-CSCs) before their transition to various progeny phenotypes. We envisage major differences in the steady state kinetics between P-SCs and P-CSCs. We further propose that P-CSCs of carcinoma are both marked and regulated by (n + c)Maspin. The concept of P-CSCs helps explain the apparent dichotomous relationships of (n + c)Maspin expression with cancer diagnosis and prognosis, and is supported by the evidence from mechanistic studies. We believe that the potential utility of (n + c)Maspin as a molecular marker of P-CSCs may significantly accelerate the advancement in our understanding of the genesis of tumor phenotypic plasticity in response to changes of tumor microenvironments (TME) or drug treatments. The vulnerabilities of the cellular state of (n + c)Maspin-expressing P-CSCs are also discussed as the rationale for future development of P-CSC-targeted chemotherapeutic and immunotherapeutic strategies.

Potential Use of Senolytics for Pharmacological Targeting of Precancerous Lesions

Senescence is a cell state that contributes to several homeostatic and pathologic processes. In addition to being induced in somatic cells in response to replicative exhaustion (replicative senescence) as part of organismal aging, senescence can also be triggered prematurely by oncogene hyperactivation or tumor suppressor dysfunction [oncogene-induced senescence (OIS)]. Consequently, senescent cells comprise a major component of precancerous lesions of skin, oral mucosa, nasopharynx, prostate, gut, and lung. Unfortunately, invasive (or minimally invasive) interventions are currently the only available approach employed to eradicate premalignant lesions that carry the potential for cancer progression. Senolytics are a newly emerging drug class capable of selectively eliminating senescent cells. Although senolytics have been successfully demonstrated to mitigate a myriad of aging-related pathologies and to cull senescent cancer cells, there is a paucity of evidence for the potential use of senolytics as a novel approach to eliminate oncogene-induced senescent cells. This Emerging Concepts commentary will 1) summarize evidence in established models of OIS including B-Raf-induced nevi, transgenic lung cancer, and pancreatic adenocarcinoma models, as well as evidence from clinical precancerous lesions; 2) suggest that OIS is targetable; and 3) propose the utilization of senolytic agents as a revolutionary means to interfere with the ability of senescent premalignant cells to progress to cancer in vitro and in vivo If proven to be effective, senolytics will represent an emerging tool to pharmacologically treat precancerous lesions. SIGNIFICANCE STATEMENT: The treatment of premalignant lesions is largely based on the utilization of invasive (or minimally invasive) measures. Oncogene-induced senescence (OIS) is one form of senescence that occurs in response to oncogene overexpression in somatic cells and is present in precancerous lesions. Although the contribution of OIS to disease progression is undetermined, recent evidence suggests that senescent cells are permissive for malignant transformation. Accordingly, the pharmacological targeting of oncogene-induced senescent cells could potentially provide a novel, less invasive, means for the treatment of premalignant disease.

Immunoexpression of Apoptosis and Cell-cycle Arrest Markers in Oral Lichen Planus

The expression pattern of a panel of 5 molecular markers (p53, cyclin D1, Ki-67, BCL-2, and BAX) was studied in samples from patients with oral lichen planus (OLP) and normal oral mucosa (NOM) of healthy controls to investigate the implications of cell cycle and apoptosis in OLP. The 59 OLP and 16 NOM biopsies were stained by an inmunoperoxidase technique for p53, cyclin D1, Ki-67, BCL-2, and BAX and assessed microscopically for semiquantitative analysis. Positivity for BCL-2 and Ki-67 was significantly more frequent in NOM than in OLP (P<0.05). p53 levels were upregulated in atrophic/erosive clinical presentations when compared with reticular presentations and in cases with discontinued inflammatory infiltrate. Multivariate analysis through logistic regression showed that BCL-2 in OLP versus NOM was the only significantly altered marker in the present cohort (adjusted odds ratio=12.42; 95% confidence interval: 2.5-61.65; P=0.002). The cell patterns in OLP and NOM are distinct according to the present molecular markers panel. The presence of BCL-2 altered expression may be related to various molecular pathways that connect/link this condition to other autoimmune disorders and also may be involved in complex roles that evoke malignant transformation of OLP.

A functional variant at the miRNA binding site in HMGB1 gene is associated with risk of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a common malignancy that has been causally associated with both hereditary and acquired factors. The high mobility group box 1 (HMGB1) gene plays an important role as a DNA chaperone to help maintain nuclear homeostasis. Altered expression of HMGB1 has been implicated in a wide range of pathological processes, including inflammation and cancer. The present study explores the impact of HMGB1 gene polymorphisms, combined with environmental risks regarding susceptibility to oral tumorigenesis. Four single-nucleotide polymorphisms (SNPs) of the HMGB1 gene, rs1412125, rs2249825, rs1045411, and rs1360485, were evaluated in 1,200 normal controls and 772 patients with OSCC. We found an association between the wild-type allele of rs1045411 and genotypes CT and CT/TT (AOR=0.754, 95% CI=0.582-0.978 and AOR=0.778, 95% CI=0.609-0.995, respectively). Additionally, bioinformatics analysis was used to characterize the functional relevance of these variants for the miRNA-505-5p binding site and transcriptional regulation by the HMGB1 3’-UTR and promoter regions. Moreover, in considering behavioral exposure to environmental carcinogens, the presence of the four HMGB1 SNPs, combined with/without betel quid chewing and smoking showed, profoundly synergistic effects on the risk of OSCC. In conclusion, we present a potential clinical relevance for HMGB1 variants in OSCC, as well as associations between HMGB1 polymorphisms, haplotypes and environmental risk factors. The finding may help in development of optimal therapeutic approaches for OSCC patients.

DNA damage marker phosphorylated histone H2AX is a potential predictive marker for progression of epithelial dysplasia of the oral cavity

AIMS

To evaluate the relationships between immunohistochemical markers related to cellular senescence, cell proliferation and histological grade of epithelial dysplasia (OD) of the oral cavity. In addition, the predictive value of these markers for progression of OD was assessed.

METHODS AND RESULTS

Retrospective immunohistochemical analyses were performed on 86 formalin-fixed paraffin-embedded specimens of OD and oral squamous cell carcinoma (OSCC) for Ki67, phosphorylated histone H2AX (γH2AX), p53, p16, trimethyl-histone H3 (Lys9) (H3K9me3) and cyclin D1 (CycD1). Three separate areas representing the highest severity of OD on each slide were annotated digitally by two independent pathologists. Mean automated histoscores of the selected markers were generated and compared to that of age-matched healthy controls (n = 24). Follow-up data of OD were retrieved and anonymized by a clinical team member and linked using unique participant identifiers. The median follow-up was 10.9 years (interquartile range: 10.1-11.5). Ki67 (P < 0.0001), γH2AX (P = 0.03) and p53 (P = 0.04) were increased significantly with higher histological grade of OD. γH2AX (P = 0.03), but not histological grade of OD (P = 0.73), was associated prospectively with disease progression. Using the median histoscore for γH2AX (median histoscore = 17) as a cut-off, histoscore ≥17 was associated with an increased risk of disease progression [hazard ratio (HR) = 3.15, 95% confidence interval (CI): 1.41-7.39, P = 0.0064].

CONCLUSIONS

Although proliferation marker Ki67, DNA damage/checkpoint markers γH2AX and p53 were increased in higher grade of OD, only γH2AX was predictive of disease progression. These observations may reflect the role of DNA replicative stress in the transformation from OD to OSCC. Larger studies should evaluate whether γH2AX can be used as a predictive marker of OD.

Combinations of SERPINB5 gene polymorphisms and environmental factors are associated with oral cancer risks

Background

We identified rs17071138 T/C, rs3744941 C/T, and rs8089104 T/C gene polymorphisms of SERPINB5 (mammary serine protease inhibitor) that are specific to patients with oral cancer susceptibility and their clinicopathological status.

Methodology/Principal findings

In total, 1342 participants, including 601 healthy controls and 741 patients with oral cancer, were recruited for this study. Allelic discrimination of rs17071138 T/C, rs3744941 C/T, and rs8089104 T/C of the SERPINB5 gene was assessed by a real-time PCR with a TaqMan assay. We found that individuals carrying the polymorphic rs17071138 and rs8089104 are more susceptible to oral cancer (OR, 1.57; 95% CI, 1.07~2.31 and OR, 1.58; 95% CI, 1.04~2.39, respectively). Among oral cancer-related risk factor exposures, the individuals carrying the polymorphic rs17071138 had 4.26- (95% CI: 1.65~11.01; p = 0.002), 2.34- (95% CI: 1.19~4.61; p = 0.01), and 2.34-fold (95% CI: 1.38~3.96; p = 0.001) higher risks of developing oral cancer.

Conclusions

Heterozygous TC of the SERPINB5 rs17071138 polymorphism may be a factor that increases susceptibility to oral cancer. Interactions of gene-to-gene and gene-to-oral cancer-related environmental risk factors have a synergetic effect that can further enhance oral cancer development.

RNA-Binding Protein FXR1 Regulates p21 and TERC RNA to Bypass p53-Mediated Cellular Senescence in OSCC

RNA-binding proteins (RBP) regulate numerous aspects of co- and post-transcriptional gene expression in cancer cells. Here, we demonstrate that RBP, fragile X-related protein 1 (FXR1), plays an essential role in cellular senescence by utilizing mRNA turnover pathway. We report that overexpressed FXR1 in head and neck squamous cell carcinoma targets (G-quadruplex (G4) RNA structure within) both mRNA encoding p21 (Cyclin-Dependent Kinase Inhibitor 1A (CDKN1A, Cip1) and the non-coding RNA Telomerase RNA Component (TERC), and regulates their turnover to avoid senescence. Silencing of FXR1 in cancer cells triggers the activation of Cyclin-Dependent Kinase Inhibitors, p53, increases DNA damage, and ultimately, cellular senescence. Overexpressed FXR1 binds and destabilizes p21 mRNA, subsequently reduces p21 protein expression in oral cancer cells. In addition, FXR1 also binds and stabilizes TERC RNA and suppresses the cellular senescence possibly through telomerase activity. Finally, we report that FXR1-regulated senescence is irreversible and FXR1-depleted cells fail to form colonies to re-enter cellular proliferation. Collectively, FXR1 displays a novel mechanism of controlling the expression of p21 through p53-dependent manner to bypass cellular senescence in oral cancer cells.

Serpin peptidase inhibitor (SERPINB5) haplotypes are associated with susceptibility to hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the second leading cause of cancer-related death worldwide. The serpin peptidase inhibitor SERPINB5 is a tumour-suppressor gene that promotes the development of various cancers in humans. However, whether SERPINB5 gene variants play a role in HCC susceptibility remains unknown. In this study, we genotyped 6 SNPs of the SERPINB5 gene in an independent cohort from a replicate population comprising 302 cases and 590 controls. Additionally, patients who had at least one rs2289520 C allele in SERPINB5 tended to exhibit better liver function than patients with genotype GG (Child-Pugh grade A vs. B or C; P = 0.047). Next, haplotype blocks were reconstructed according to the linkage disequilibrium structure of the SERPINB5 gene. A haplotype “C-C-C” (rs17071138 + rs3744941 + rs8089204) in SERPINB5-correlated promoter showed a significant association with an increased HCC risk (AOR = 1.450; P = 0.031). Haplotypes “T-C-A” and “C-C-C” (rs2289519 + rs2289520 + rs1455555) located in the SERPINB5 coding region had a decreased (AOR = 0.744; P = 0.031) and increased (AOR = 1.981; P = 0.001) HCC risk, respectively. Finally, an additional integrated in silico analysis confirmed that these SNPs affected SERPINB5 expression and protein stability, which significantly correlated with tumour expression and subsequently with tumour development and aggressiveness. Taken together, our findings regarding these biomarkers provide a prediction model for risk assessment.

Increased expression of oncogene-induced senescence markers during cervical squamous cell cancer development

PURPOSE

To investigate the expression of p15(INK4b), p16(INK4a) and p21(Waf1/Cip1) in specimens from cases of normal cervical epithelium (NCE), cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC), and to evaluate whether there is evidence implicating oncogene-induced senescence (OIS) in cervical squamous cell cancer development.

METHODS

The immunohistochemical expression of p15(INK4b), p16(INK4a) and p21(Waf1/Cip1) were investigated in formalin-fixed paraffin-embedded specimens from 19 NCE, 51 CIN and 21 SCC cases, respectively. Comparisons among different groups for each marker were performed with Chi-square test.

RESULTS

The expression of p15(INK4b), p16(INK4a) and p21(Waf1/Cip1) were significantly higher in both CIN and SCC compared to NCE. Furthermore, the expression of p15(INK4b) and p21(Waf1/Cip1) was significantly higher in CIN П compared to CIN І, and these expressions were statistically higher in CIN Ш compared to CIN П, respectively. The p16(INK4a) expression was significantly higher in CIN Ш compared to CIN І.

CONCLUSIONS

The results suggested that the senescence programs mediated by p15(INK4b), p16(INK4a) and p21(Waf1/Cip1) were activated during the stage of CIN and SCC, and demonstrated that senescence may play important role in preventing from NCE to SCC.

Urban legends series: oral leukoplakia

To date, the term oral leukoplakia (OL) should be used to recognize 'predominantly white plaques of questionable risk, having excluded (other) known diseases or disorders that carry no increased risk of cancer'. In this review, we addressed four controversial topics regarding oral leukoplakias (OLs): (i) Do tobacco and alcohol cause OLs?, (ii) What percentage of OLs transform into oral squamous cell carcinoma (OSCC)?, (iii) Can we distinguish between premalignant and innocent OLs?, and (iv) Is proliferative verrucous leukoplakia (PVL) a specific entity or just a form of multifocal leukoplakia? Results of extensive literature search suggest that (i) no definitive evidence for direct causal relationship between smoked tobacco and alcohol as causative factors of OLs, (ii and iii) the vast majority of OLs follow a benign course and do not progress into a cancer, and no widely accepted and/or validated clinical and/or biological factors can predict malignant transformation, and (iv) the distinction between multifocal/multiple leukoplakias and PVL in their early presentation is impossible; the temporal clinical progression and the high rate of recurrences and development of cancer of PVL are the most reliable features for diagnosis.